Some portable communication terminals including a smartphone and a game machine have short-range wireless communication functions such as Bluetooth (Registered Trademark), and can perform a data exchange with another communication terminal. The data exchange is possible even for a short time when the communication terminals pass by each other. Such a data exchange is called passing-by communication (refer to, for example, Patent Documents 1 to 3).
On the other hand, communication tools using the Internet which are called SNS (Social Networking Service) are widely used.
By taking advantage of the passing-by communication described above to exchange identification data such as an account name and a user ID of SNS, it is possible to provide a new opportunity for users who participate in the same event such as watching a soccer game and a concert to communicate with each other.